RCA 21CT55 B8802897 is Alive!

[miniman82]

Originally Posted by Electronic M

....Video resolution(visual detail) in analog TV is directly related to bandwidth...

To a point: remember, there are only so many phosphor dots.

[Tomcomm]

Originally Posted by miniman82

To a point: remember, there are only so many phosphor dots.

This statement suggests the CRT is dot-limited in its ability to display the picture quality improvement of the CTC2B’s wide-band IQ demodulation chassis. The 21FBP22 spec places the distance of adjacent RGB dot clusters at .029 inches. Since the horizontal screen width is 19.25 inches, a maximum TV line without overscan is composed of 664 clusters which will produce 332 line-pairs of resolution. At the accepted TV value of 80 line-pairs per mhz of video bandwidth, the 21FBP22 will support up to 4.15 mhz video bandwidth! This is sufficient for 4.10mhz video of high quality B&W TV and way sufficient for the limited 3.2mhz Color TV luminance video. This CRT easily supports the CTC2B I chroma channel’s 1.3mhz video bandwidth to produce 104 line-pairs of I chroma resolution. This resolution is far greater then the 40 line-pair resolution produced by the .5mhz R-Y, B-Y chroma bandwidths of the CTC4 and later RCA roundys.

Obviously, the quanity of phospher dots can’t possibly limit the ability of a knowable observer viewing a 20in CRT at a distance of less than 40in to determine relative picture quality. The CTC2B’s wide bandwidth I chroma resolution is 260% higher then the CTC4’s and later equi-chroma bw CTV’s resolution. Of course, this difference is most apparent on chroma resolution charts but will certainly be noticeable in any high quality natural scene and will be manifested by obvious reduction in picture quality.